This invention relates to electrochemical cells or batteries and more particularly, to a keying system to insure proper interconnection of battery cells.
Electrochemical cells and batteries are utilized in numberous applications for the storage of electrical energy, the term battery herein referring to a series of cells which are electrically coupled. In one form of battery, electrical connection is made by terminals in the form of a pair of studs protruding from one end of side of the cell. By way of example, these studs may be threaded to permit the securing of a connecting link to the stud by threaded nuts. In an alternative cell, the terminals may take the form of tabs which may be bent to permit a spot welding of a connecting link thereto.
A problem arises in the interconnection of the foregoing cells, particularly in the manufacture of electronic systems requiring the interconnection of a series of the cells to form a battery of increased voltage required to operate the electronic system. Metallic links usually are employed to join the individual cells into a battery by connecting the positive terminal of one cell to the negative terminal of the next cell. In the manipulation of the coupling link by a person assembling the battery, it is not uncommon for a link to inadvertently contact two studs of a single cell with a resulting shorting or possible damage to the cell. Nor is it uncommon for a connection of the link to be made between two positive terminals, or two negative terminals, rendering the battery inoperative. Such misconnections occur because it is all too easy for a worker on a busy production line to make a mistake by erroneously interconnecting two terminals which have identical or similar appearance. Also, it should be appreciated that since interconnecting links are sometimes quite small and thin, they may be difficult to handle. A dropped or misplaced connection can readily contact terminals of the battery and short it out.